Flowmaster 717857 FlowFX Cat-Back Exhaust Kit Review: Transform Your Silverado’s Sound and Performance

When we first bolted on the Flowmaster 717857 FlowFX Cat-Back Exhaust Kit to our 2017 Chevy Silverado 1500 with the 5.3L V8, we knew within the first startup that this was going to be something special. The deep, authoritative rumble that emerged wasn’t just noise—it was a symphony of American V8 muscle that brought a genuine smile to our faces.

After several months of daily driving, highway cruising, and spirited acceleration runs, we’ve developed a comprehensive understanding of what this exhaust system delivers. Whether you’re looking to wake up your truck’s personality, squeeze out some additional horsepower, or simply enjoy a more engaging driving experience, the Flowmaster 717857 deserves serious consideration.

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What Makes the Flowmaster FlowFX Stand Out?

The FlowFX series represents Flowmaster’s effort to bridge the gap between mild-mannered daily drivers and full-throated performance exhausts. During our testing, we discovered that this particular kit strikes an impressive balance—delivering that classic Flowmaster sound without the drone that can make highway drives uncomfortable.

The system’s 3-inch mandrel-bent 409 stainless steel tubing provides excellent exhaust flow while resisting corrosion far better than aluminized steel alternatives. We’ve driven through countless rainstorms, road salt, and temperature extremes, and the system shows no signs of rust or deterioration. The 4.5-inch black ceramic-coated stainless steel tips add a refined aesthetic touch that complements the Silverado’s aggressive rear stance perfectly.

Installation: Easier Than Expected

We tackled the installation ourselves on a Saturday afternoon, and with basic hand tools and a quality jack stand setup, the entire process took approximately three hours. The kit is designed as a true bolt-on system—no cutting, welding, or fabrication required.

The factory-style hangers integrate seamlessly with existing mounting points, and all necessary hardware comes included in the box. We did apply a thin coat of anti-seize to all bolts, which we’d recommend to anyone planning future removal. The fit was impressively precise, with clearance exactly where it needed to be and no modifications required for proper alignment.

One tip from our experience: having a second set of hands makes supporting the system during installation significantly easier, though it’s certainly possible as a solo project if you use a transmission jack or similar support.

Sound Quality: The Heart of the Experience

This is where the Flowmaster 717857 truly shines. At idle, the exhaust produces a throaty burble that’s noticeably deeper than stock but not obnoxiously loud. Your neighbors won’t hate you for early morning cold starts, but you’ll definitely notice the difference.

During normal driving conditions—cruising at 40-50 mph through town—the exhaust maintains a pleasant rumble that reminds you you’re driving a V8 without overwhelming conversation or the stereo. We measured interior sound levels, and they remained remarkably civilized during typical driving.

Where this system really comes alive is under acceleration. Roll into the throttle, and you’re rewarded with a progressively aggressive growl that builds beautifully through the RPM range. The tone is distinctly American V8—muscular, confident, and addictive. We found ourselves taking longer routes just to hear it work.

Highway drone—the dreaded nemesis of many performance exhausts—is impressively minimal. At 70-75 mph on the interstate, there’s a subtle presence but nothing fatiguing during long drives. We completed several 300+ mile trips and never experienced listening fatigue or felt the need to turn up the radio to compensate.

Performance Gains: More Than Just Sound

While most truck owners choose aftermarket exhausts primarily for sound enhancement, the Flowmaster 717857 delivers legitimate performance benefits as well. The larger 3-inch diameter piping and mandrel-bent construction reduce exhaust restriction compared to the factory system.

During our testing, we noticed improved throttle response, particularly in the mid-range where most daily driving occurs. The engine feels freer to breathe, with slightly quicker acceleration when merging or passing. While we didn’t conduct dyno testing, the seat-of-the-pants improvement is noticeable—likely in the range of 8-12 horsepower and a similar torque increase.

Fuel economy remained essentially unchanged during our monitoring period. Over several thousand miles, we tracked variations of less than 0.3 mpg compared to our pre-installation baseline—well within normal fluctuation ranges.

Construction Quality: Built to Last

The 409 stainless steel construction impressed us from the moment we unboxed the system. The welds are clean and consistent, the tubing thickness feels substantial, and the overall fit and finish speak to quality manufacturing.

The mandrel-bent tubing maintains consistent diameter throughout all bends, which not only optimizes exhaust flow but also demonstrates attention to engineering detail. Cheaper systems often use crush-bent pipes that reduce internal diameter at bend points, restricting flow and reducing performance.

Those 4.5-inch black ceramic-coated tips aren’t just for show—they’ve maintained their appearance beautifully despite exposure to exhaust heat and environmental elements. The ceramic coating resists discoloration far better than chrome or raw stainless steel, keeping that aggressive black appearance fresh.

Compatibility Details You Need to Know

This specific kit (part number 717857) is engineered for 2014-2019 classic body Chevy Silverado and GMC Sierra 1500 trucks equipped with either the 4.3L V6 or 5.3L V8 engines. Our test vehicle was a 2017 Silverado 1500 Crew Cab with the 5.3L engine, and fitment was absolutely perfect.

Important note: This system is designed for standard bed configurations and may require verification for short bed models. Additionally, it’s compatible with two-wheel-drive and four-wheel-drive models, though clearance should be verified on lifted or significantly modified trucks.

The kit does not include catalytic converters—it’s a cat-back system that connects behind your factory catalytic converters, maintaining emissions compliance in all 50 states. This makes it a legal modification that won’t trigger check engine lights or cause inspection issues.

Comparing Value Against the Competition

We’ve tested several exhaust systems in this category, and the Flowmaster 717857 occupies a sweet spot in both performance and pricing. It’s positioned below premium brands like Borla and Corsa but delivers sound quality and construction that punches above its price point.

Compared to budget options from lesser-known manufacturers, the Flowmaster’s superior materials, precise fit, and refined sound tuning justify the price differential. You’re getting genuine engineering expertise and decades of exhaust design experience, which translates to a better overall product.

The lifetime warranty from Flowmaster adds significant value—they stand behind their products, and their customer service reputation is solid within the enthusiast community.

Real-World Durability Testing

After months of exposure to varying conditions—winter road salt in the north, summer heat in the south, rain, snow, and everything between—the system shows zero corrosion or degradation. The 409 stainless steel construction is proving its worth as a long-term investment.

We’ve encountered no rattles, no loose hangers, and no changes in sound quality that would indicate internal deterioration. The tips still look factory-fresh, and the system maintains proper alignment with no sagging or shifting.

The welds, which are often the weak points in exhaust systems, remain perfect with no cracking or separation despite thermal cycling and vibration exposure.</p